Acker will play an attractive psychologist who caters to the rich and powerful. When the machine spits out her number, Reese (Jim Caviezel) must keep her safe from several clients who could potentially kill to keep their secrets safe.Besides her work on Angel and Alias, Acker has also recurred on such series as Dollhouseand Happy Town. Most recently, Acker guest-starred on Grimmand Once Upon a Time. She's currently appearing on the big screen in The Cabin in the Woods.Person of Interest airs Thursdays at 9/8c on CBS. The season finale is slated to air May 17.